We are experiencing intermittent access failures on our domain faunapro.com.br. Some users are unable to load the site while others on the same network can — the behavior is non-deterministic and device-dependent.
Root cause identified: DNS resolution of www.faunapro.com.br follows this chain:
www.faunapro.com.br → CNAME cname.vercel-dns.com → 66.33.60.194 ← TLS handshake times out (port 443 unreachable) → 76.76.21.93 ← responds normally
The IP 66.33.60.194 is being returned by cname.vercel-dns.com in round-robin rotation but does not complete the TLS handshake. The connection attempt on port 443 times out after ~300 seconds with no response.
Reproduction steps: Resolve www.faunapro.com.br → obtain 66.33.60.194 curl -v https://www.faunapro.com.br (when routed to 66.33.60.194) Result: Connection timed out after 300000ms — no TLS response
Evidence collected: curl -v https://www.faunapro.com.br → timeout (when resolving to 66.33.60.194) curl -v https://www.faunapro.com.br → success (when resolving to 76.76.21.93) Reverse DNS lookup on 66.33.60.194 → NXDOMAIN Issue is consistent and reproducible across multiple devices and networks
Current workaround applied: We temporarily replaced the CNAME record with an A record pointing directly to 76.76.21.93 to restore service. We intend to revert to the CNAME once this is resolved.
Request: Please investigate and remove 66.33.60.194 from the cname.vercel-dns.com resolution pool, or restore TLS service on that edge node.
Project details: Domain: faunapro.com.br / www.faunapro.com.br Vercel IP affected: 66.33.60.194 Vercel IP working: 76.76.21.93 SSL Certificates on account: cert_3t3E4Bp1Vy1A9XeAXE7c2QdB / cert_nj8l4K3j267uNoHyH9g4aYtl
Thank you.